Your question makes no sense. There is no specific time any consumer
"should" send a cancel request. The consumer listens for as long as
you're interested in receiving updates. When you decide you're not
interested any more, you can just shutdown the consumer.

thanks for reply,
can consumer be configed so that it will stop after synced OK
instead of being shutdown ??

Again, what you are asking makes no sense.

The point of replication is for the consumer to stay in "sync" with the
master. Stopping the synchronization is not a desired behavior. Why do
you want to make your replicas stop being updated?